Title of Invention	FILAMENT-FORMING POLYESTERS AND COPOLYESTERS AND PROCESS FOR THEIR PRODUCTION
Abstract	Filament-forming polyesters and copolyesters are provided that contain chemical modi- fiers in the form of condensed-in chain-branching agents and physical modifiers in the form of polymer additives that do not substantially form chemical bonds with the fila- ment-forming polyesters and copolyesters, whereby the ratio of the weight percentages, referred to the filament-forming polyesters and copolyesters, of chemical to physical modifiers is between 0.001 and 0.5. They are excellently suited for high-speed spinning of textile and industrial yarns with winding speeds of 2500 to 10000 mlmin and for downstream processes such as drawing and texturizing.

Title of Invention

FILAMENT-FORMING POLYESTERS AND COPOLYESTERS AND PROCESS FOR THEIR PRODUCTION

Abstract

Filament-forming polyesters and copolyesters are provided that contain chemical modi- fiers in the form of condensed-in chain-branching agents and physical modifiers in the form of polymer additives that do not substantially form chemical bonds with the fila- ment-forming polyesters and copolyesters, whereby the ratio of the weight percentages, referred to the filament-forming polyesters and copolyesters, of chemical to physical modifiers is between 0.001 and 0.5. They are excellently suited for high-speed spinning of textile and industrial yarns with winding speeds of 2500 to 10000 mlmin and for downstream processes such as drawing and texturizing.

Full Text	Description: The invention relates to filament-forming polyesters and copolyesters containing chemical modifiers in the form of condensed-in chain-branching agents and physical modifiers in the form of polymer additives that do not substantially form chemical bonds with the filament-forming polyesters and copolyesters, and a process for their production. The invention further relates to the use of these polyesters and copolyesters for high-speed spinning of textile and industrial yarns. Filament-forming chain-branched polyesters and copolyesters having very slight amounts of chain-branching agents are known. DE 27 28 095 A1 describes filament-forming chain-branched polyesters and copolyesters having very slight amounts of pentaerythritol or other polyfunctional compounds such as glycerin, trimethylol propane, or mellitic acid. Using the tetrafunctional branching agent pentaerythritol as a chain-branching agent, high residual elongations and resulting productivity gains are obtained from added amounts ranging from 500 to 625 ppm, whereas with lower added amounts ranging from about 100 to 200 ppm the residual elongations and resulting productivity gains are reduced considerably (see Table I of DE 27 28 095 A1). In the case of high added amounts of pentaerythritol, the high degree of branching of the corresponding polyesters results in properties for the POY yarns used in further processing that differ considerably from the conventional polyester yarns, whose valued and proven proper- ties it is naturally desirable to maintain, and unacceptable interactions of the yarn properties develop at spinning speeds of 4023 m/min or higher (see Table II of DE-OS 27 28 095). Progress in this direction is shown by WO 98/47936, which discloses filament-forming chain-branched polyesters and copolyesters with a molecular weight of > 10000 and which are obtained by condensing into the polyester-forming starting components 50 to 500 ppm of one or more of the chain-branching agents di-, tri- or tetrapentaerythritol added during polymer production. According to WO 98/47936, these polyesters and copolyesters are excellently suited for high-speed spinning of textile and industrial yarns with winding speeds of 2500 to 10000 m/min. However, the increased crystallinity of such modified polyesters and copolyesters in processes downstream from the spinning process, in particular in texturizing, can result in processing problems, which in adverse situations can lead to partial or total loss of the productivity gains realized during spinning. There are also a number of publications known in the art in which the filament-forming polyesters and copolyesters contain physical modifiers in the form of polymer additives, which do not substantially form chemical bonds with the filament-forming polyesters and copolyesters. WO 93/19231 describes fibers made primarily from polyethylene terephthalate as a fiber polymer, the fibers characterized in that they contain 0.1 to 5% by weight, referred to the fiber polymer, of a 50 to 90% imidized polymethacrylic acid alkyl ester mainly in interstitial form. According to this document, spinning at very high rates (such as 8000 m/min) is possible while maintaining conventional thread-breakage counts. DE 197 33 799 A1 makes known the use of copolymers of methyl methacrylate, maleic acid anhydride, and/or maleic imides and possibly other ethylenic unsaturated and therefore copolymerizable monomers as additives to fiber polymers based on polyal- kylene terephthalates in amounts of 0.1 to 5% by weight. The addition of these copolymers is intended to improve the melt-spinning properties of polyester filament yarns after high-speed and super-high-speed spinning with drawing-off speeds of 500 to 10000 m/min. Finally, DE 197 07 447 A1 discloses copolymers added to the polyester or polyamide in amounts of 0.05 to 5 percent by weight, and constructed from at least two of the following monomer units: A = monomer of acrylic acid or methacrylic acid alkyl ester type B = monomer of maleic acid or maleic acid anhydride type C = monomer of styrene type with = to 90% by weight A, 0 to 40% by weight B, and 5 to 85% by weight C (totaling 100%). According to the latter document, these physical modifiers do not restrict in particular the behavior in further-processing steps, and this despite increased spinning speed. According to DE 197 07 447 A1, in the case of polyethylene terephthalate (PET) as a matrix polymer, a slight fraction of branching components can be included, such as polyfunctional acids like trimellitic or pyromellitic acid, ortri- ortetravalent alcohols such as trimethylol propane, pentaerythritol, or corresponding hydroxy acids. In the spinning of polyesters and copolyesters, in particular polyethylene terephthalate, modified with physical modifiers, as disclosed in WO 93/19231, DE 19733 799 A1, and DE 197 07 447 A1, however, problems can arise during winding , which manifest themselves especially at higher speeds, i.e., above 3000 m/min, particularly above 5000 m/min. On the one hand, there is an increase of so-called slips. Slips are known to those skilled in the art as flaws that arise during winding when a filament section slips laterally. This places problem-free pull-off of the material in further processing in question. On the other hand, a further disadvantage in spinning, particularly in high-speed spinning, is the tendency of the physically modified polyesters and copolyesters to form swells during winding onto the spool. Swells are likewise known to those skilled in the art as spooling flaws and lead for example to problems in packaging and shipment of the finished spools. The object of the present invention is to provide new filament-forming polyesters and copolyesters which at least reduce the previously described disadvantages in the prior art. Surprisingly, it was found that the object of the invention can be satisfied by filament-forming polyesters and copolyesters containing chemical modifiers in the form of con-densed-in chain-branching agents and physical modifiers in the form of polymer additives that do not substantially form chemical bonds with the filament-forming polyesters and copolyesters, these polyesters and copolyesters being characterized in that the ratio of the weight percentages, referred to the filament-forming polyesters and copolyesters, of chemical to physical modifiers is between 0.001 and 0.5. Preferred polyesters and copolyesters are obtained by setting the ratio of the weight percentages of chemical to physical modifiers, each referred to the filament-forming polyesters and copolyesters, between 0.005 and 0.25, and a ratio between 0.015 and 0.05 is especially preferred. Even at high winding speeds of 2500 to 10000 m/min, the polyesters and copolyesters of the invention surprisingly do not exhibit the problems known in the prior art that result when using only one of the two modifiers or a combination of chemical and physical modifiers outside the claimed range. The advantageous behavior of the polyesters and copolyesters in accordance with the present invention manifests itself in particular in practically slip-free winding at spinning speeds between 2500 and 10000 m/min, in particular between 3000 and 6000 m/min. The crystallinity of these polyesters and copolyesters is such that, even in steps downstream from the spinning process such as tex- turizing, a processing speed can be attained that is at least at the level of unmodified polyesters and copolyesters. The present invention therefore makes it possible to maintain the increase in spinning speed known in the prior art by adding chemical or physical modifiers and at the same time, by setting a specific quantity ratio between physical and chemical modifiers, to provide polyesters and copolyesters that are capable of solving the previously described problems in the prior art. Polyesters and copolyesters with a weight ratio according to the invention are not disclosed by DE 197 07 447 A1 and are also not suggested by this specification. The assumed cause for the speed-increasing action of certain physical and chemical modifiers is known to those skilled in the art from WO 93/19231 and WO 98/47936, for example. In both cases, the residual elongation of polyesters and copolyesters modified in this manner is higher compared to the unmodified compounds. To attain the same residual elongation as with unmodified polyesters and copolyesters, the modified polyesters and copolyesters can therefore be wound up at correspondingly higher speed, thereby increasing the throughput in melt spinning. One service provided by the polyesters and copolyesters according to the invention is that the effects of both modifiers in increasing spinning speed are also maintained in the ratio according to the invention. This means that the overall increase in melt-spinning throughput can indeed be the sum of the contributions of both modification types. A synergistic effect with respect to spinning speed, i.e., an increase over and above the mere additive effect of both modifiers, is conceivable using the polyesters and copolyesters of the invention, but it could not be experimentally verified up to now. However, it has been noted that the polyesters and copolyesters according to the present invention exhibit the aforementioned advantages over and above the mere addition of the effects increasing spinning speed One skilled in the art can determine the concentrations of chemical and physical modifiers by simple trials. The polyesters and copolyesters of the invention generally contain the chemical modifiers in weight percentages between 0.005 and 0.05. An amount of 0.005 to 0.025 is preferred, and 0.005 to 0.015, for example 0.011% by weight (110 ppm), is even more preferred. The weight percentages are referred in each case to the filament-forming polyesters and copolyesters. The physical modifiers are used in amounts between 0.1 and 5% by weight, referred to the filament-forming polyesters and copolyesters. A range of 0.1 to 1% by weight is preferred, and 0.3 to 1% by weight, for example 0.7% by weight (7000 ppm) is even more preferred. Of course, several different chemical and/or physical modifiers can be present simultaneously in the polyesters and copolyesters of the invention, as long as the weight ratios remain in the claimed ranges. It is preferable, however, to use only one type of chemical and physical modifier, respectively. The chemical modifiers are chain-branching agents, preferably low-molecular, and therefore contain at least three functional groups that are suitable for reacting with the polyester-forming starting components. In this case, and for the subsequently cited chemical modifiers, the number of functionalities or functional groups in each case refers of course to the number before the reaction with the polyester- or copolyester-forming starting components. Preferred polyester-forming starting components are those diols and dicarboxylic acids, or derivatives thereof such as dicarboxylic acid diesters, that lead to the formation of polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, poly(ethylene-2,6-naphthalene dicarboxylate), poly(butylene-2,6-naphthalene dicar-boxylate), poly(1,4-dimethylenecyclohexane terephthalate), or polyester blends thereof on the basis of high homopolyester fractions of at least 90 mole percent. The remaining dicarboxylic-acid and diol components of these polyester blends can, in amounts up to 10 mole percent, be the conventional co-components in producing drawn polyester structures, such as isophthalic acid, p,p'-diphenyl dicarboxylic acid, all possible naphthalene dicarboxyiic acids, hexahydroterephthalic acid, adipic acid, sebacic acid, and glycols such as trimethylene, tetramethylene, hexamethylene, and decamethylene glycol. Suitable chain-branching agents that can react with the polyester-forming starting components include chemical modifiers that have at least three ester-forming hydroxyl or carboxyl groups. Preferred modifiers are trimellitic acid, pyromellitic acid, trimethylol propane, pentaerythritol, glycerin, or the corresponding hydroxy acids. Of course, the group of chain-branching agents need not be limited to compounds having ester-forming hydroxyl and carboxyl groups. Also possible, of course, are other functional groups such as amino or isocyanate groups. The selection of the chemical modifiers is limited only by the requirement that the stability of the compounds used be sufficient to withstand the reaction conditions prevailing in polyester synthesis, such that a branching reaction is substantially possible. Preferred for the present invention, however, are polyesters and copolyesters modified with chemical modifiers having at least six ester-forming hydroxyl groups. Of these latter chemical modifiers, those selected from the group comprising dipentae-rythritol, tripentaerythritol, and tetrapentaerythritol are especially preferred. Such modifiers are known from WO 98/47936, for example. The production of chain-branched polyesters and copolyesters is known per se. Since the chain-branched polyesters and copolyesters can also be categorized in particular as chemically modified homopolyesters and copolyesters, it is not even necessary when producing them to modify the production method for the homopolyesters and copolyesters concerned, such as the transesterification and polycondensation conditions. The only difference is that the chain-branching agents be added in the required weight percentages to the corresponding polyester-forming starting components during polyester production, which is otherwise conventional. This is illustrated using the especially preferred chain-branched polyester in the scope of the present invention, which is obtained by adding chain-branching agent(s) leading to formation of polyethylene tereph-thalate to the polyester-forming starting components. The production of polyethylene terephthalate can proceed in a known manner in two reaction stages. The first reaction stage, which can be conducted continuously or discontinuous^, consists in the transesterification of dimethyl terephthalate with ethylene glycol to form bis(2-hydroxyethyl) terephthalate using transesterification catalysts at 150-200°C, for example, or in the direct esterification of terephthalic acid with ethylene glycol at about 260°C under pressure, which generally requires no catalyst and which also forms bis(2-hydroxyethyl) terephthalate. Through oligocondensation reactions, which take place under the transesterification and direct esterification conditions themselves, lesser or greater amounts of linear oligomers of bis(2-hydroxyethyl) terephthalate are formed in addition. A preferred embodiment according to the invention consists in adding the chain-branching agent(s), before or during the transesterification reaction or the direct esterification, to the polyester-forming starting components, in the present case to dimethyl terephthalate and ethylene glycol or to terephthalic acid and ethylene glycol, such that a uniformly reacting mixture can develop. After transesterification has ended, it is advantageous to block, in a manner known per se, any transesterification catalysts present by adding one or more phosphorus compounds. Blocking agents include in particular carbethoxymethyl diethyl phosphonate, di(polyoxyethylene)hydroxymethyl phosphonate, tetraisopropyl methylene diphospho-nate, phosphonoacetic acid ethyl ester and/or H3P04, whereby a concentration of added P of 30-50 ppm is generally sufficient. If the production of bis(2-hydroxyethyl) terephthalate and its. oligomers is conducted by adding ethylene oxide to terephthalic acid, terephthalic acid and ethylene oxide by nature represent the polyester-forming starting components. The term polyester-forming starting components fundamentally includes all dicarboxylic-acid and diol derivatives, for example also dicarboxylic acid chlorides or diol diacetates, that are suited to forming the polyesters and copolyesters known per se, which in turn are subjected during the polyester and copolyester synthesis to a modification by the chain-branching agents. The second reaction stage, which can be conducted continuously or discontinuously, consists in the polycondensation of bis(2-hydroxyethyl) terephthalate and its oligomers to form polyethylene terephthalate at 280~290°C, for example, in a vacuum using known polycondensation catalysts. A further preferred embodiment of the invention consists in the possibility of adding the chain-branching agent(s) to the polyester-forming starting components, in the present case to bis(2-hydroxyethyl) terephthalate and its oligomers, even before this melt polycondensation. While addition of the chain-branching agents in the initial part of the polycondensation stage is also possible in principle, it is not as preferred. The chain-branched polyethylene terephthalate produced in this manner has an intrinsic viscosity of 0.70 to 0.75, corresponding to a relative solution viscosity of 1.63 to 1.70, measured in 1% meta-cresol solution at 20°C. If the chain-branched polyethylene terephthalate is to be used to manufacture industrial yarns, such as for use in tire cords, its molecular weight must be increased in a manner analogous to the case of polyethylene terephthalate. This can be achieved using processes known per se developed for polyethylene terephthalate, including its conversion with agents that increase the degree of polymerization, such as 2,2'-bis(2-oxazoline), in accordance with EP-A-0 169 415. The required increase in intrinsic viscosity to 0.95-1.05, for example, corresponding to a relative solution viscosity of 1.86 to 2.05, measured in 1% meta-cresol solution at 20°C, is preferably achieved using a final polycondensation in the solid phase, as is also the practice for polyethylene terephthalate. In this case, the granular chain-branched polyethylene terephthalate is heated in a vacuum or an inert gas stream to temperatures below the melting point, such as to 230°C. The second component in the filament-forming polyesters and copolyesters of the invention is represented by the physical modifier. The physical modifiers are compounds, preferably polymeric, that do not substantially form chemical bonds with the filament-forming polyesters and copolyesters. They are generally only partially soluble in the matrix polymer formed from the filament-forming polyesters and copolyesters. In order for these physical modifiers or additives to be effective in such a way that leads to an increase in spinning speed and'throughput during melt spinning, the interface between the polymer matrix and physical modifiers should be as large as possible. In the case of polymer additives, a large interface is typically attained if these additives form fibrils during the spinning process in which the ratio of surface area to volume is large. Suitable additives must therefore, of course, be plastic at the melt-spinning temperature. It has proven advantageous for the ratio of the zero shear-rate viscosity of the additive to the zero shear-rate viscosity of the matrix polymer (e.g., the chemically modified or unmodified polyethylene terephthalate) to be between 0.01 and 5, preferably between 0.5 and 2, at the spinning temperature. The zero shear-rate viscosity of the polymers is determined in this case using the method described in G. Bohme, Stromunqsmechanik nicht-newtonscher Fluide [Flow Mechanics of Non-Newtonian Fluids], Verlag Teubner Studienbucher (1981). Another important criterion in selecting the physical modifier is that the additive solidifies significantly before the surrounding polymer matrix during the spinning process. For one skilled in the art, this means that the solidification temperature (i.e., the increase in zero shear-rate viscosity towards infinity) of the additive takes place at higher temperatures than the corresponding zero shear-rate viscosity increase of the surrounding matrix polymer. The glass transition temperature of the additive should be higher than that of the matrix polymer. In addition to the previously cited, general parameters for selecting suitable physically effective additives, at least one of the following criteria, which can be determined by measurement and/or calculation and which describe the interactions between the physical modifier (additive) and the matrix polymer, should be fulfilled. For one, the interface thickness a, between the additive and surrounding matrix should be in the range from 6 to 50 nm, preferably from 10 to 15 nm, in'the tanh interface profile at the spinning temperature. Methods for experimental characterization of interface thicknesses are known to those skilled in the art. For example, X-ray or neutron reflection, nuclear reaction analysis, NMR, or electron transmission microscopy. These methods are extremely complex and expensive, however. It has proven advantageous, therefore, to estimate the interface thickness using mean-field theory. In a 2-phase (phases 1 and 2), 2-component (components A and B) system, the following tanh interface profile applies: where O(z) = volume fraction at z z = depth perpendicular to the phase interface (z = 0 at phase interface) a{ = interface thickness Oi* = bulk volume fraction of component (A or B) in phase i For the interface thickness a; between two polymer components A and B (D. Broseta, G. Fredrickson, E. Helfand, L. Leibler, Macromolecules 23, 132 (1990), Ralf Schnell dissertation 1997, Johannes Gutenberg University, Mainz (Germany), the following applies: where a; = interface thickness b = mean Kuhn segment length (approx. 0.7 nm) c = correction factor (= 9 for the limiting case in which the gyration radius of the chains is much smaller that the interface thickness) (= 6 in the case of strongly incompatible polymers, in which the interface thickness is significantly smaller that the gyration radius) %AB = Flory-Huggins interaction parameter between the polymer components A and B Nj = Degree of polymerization of the polymer component i The Flory-Huggins interaction parameter required in the calculation can be estimated as follows using the solubility parameters of the polymer components A and B: where ^AB = Flory-Huggins interaction parameter between the polymer components A and B Vref = Reference volume (30 ccm/mol, for example, provides good results for the well-characterized polystyrene/polymethyl methyacrylate system. According to Bicerano, however, 100 ccm/mol is also used.) 5j = solubility parameter of the polymer component i (according to J. Bicerano, Prediction of Polymer Properties, Marcel Dekker Verlag, Inc., New York (1993)) R = gas constant (8.314 JK-1mol-1) T = temperature in Kelvin The polymer phases A and B are generally more compatible the smaller the difference of their solubility parameters and the higher the temperature. ' A further criterion for selecting suitable physical additives is the interfacial tension y between the additive and the surrounding polymer matrix. This interfacial tension should be in the range from 0.8 mN/m to 0.008 mN/m, preferably 0^5 to 0.3 mN/m, at the spinning temperature. The interfacial tension is measured using the pendant or spinning drop geometry method (A. Stammer, dissertation 1997, Johannes Gutenberg University, Mainz (Germany)). In practice, however, the experimentally simpler extrapolation of temperature-dependent contact-angle studies to the spinning temperature has proven very helpful. Furthermore, the interfacial tension yean be estimated, analogously to the interface thickness a^ using mean-field theory (D. Broseta, G. Fredrickson, E. Helfand, L. Leibler, Macromolecules 23, 132 (1990)): where y = interfacial tension k = Boltzmann constant T = temperature in Kelvin XAB = Flory-Huggins interaction parameter between the polymer components A and B N, = degree of polymerization of polymer component i The final criterion for selecting the physical modifiers is the adhesion between the phases. This phase adhesion should exceed 30 J/m2, preferably even80 J/m2. The adhesion between polymers is determined using the asymmetric double cantilever beam (ADCB) method as described in H. R. Brown, Annual Reviews in Materials Science 21. 463 (1991). In this case, tempering to the spinning temperature-is first performed and the adhesion between the polymers is then measured at room temperature. Suitable physical additives for producing the filament-forming polyesters and copolyesters of the invention can be found in patent specifications WO 93/19231, WO 98/27158, DE 197 33 799 A1, DE 197 07 447 A1, and EP 0 047 464 B2, for example. Preferred polyesters and copolyesters are obtained when the physical modifier consists of substantially imidized polymethacrylic acid alkyl esters that are 50 to 90% imidized by converting polymethacrylic acid esters whose ester group contains an alcohol with 1 to 6 C atoms with a primary amine with 1 to 3 C atoms. This physical additive and its use for polyethylene terephthalate is described in detail in WO 93/19231, to which explicit reference is hereby made. Other preferred polyesters and copolyesters are obtained in that the physical modifier is a copolymer made from methyl methacrylate, styrene, and acrylonitrile, whereby this copolymer is composed of 50 to 98% by weight methyl methacrylate, 1 to 50% by weight styrene, and 2 to 30% by weight acrylonitrile (totaling 100%). Especially preferred as a physical modifier is a copolymer composed of 80% by weight methyl methacrylate, 15% by weight styrene, and 5% by weight acrylonitrile. Finally, filament-forming polyesters and copolyesters are preferred in which the physical modifier is a copolymer made from methyl methacrylate and acrylonitrile, whereby this copolymer is composed of 80 to 98% by weight methyl methacrylate and 2 to 20% by weight acrylonitrile (totaling 100%). The molecular weight of the copolymers made from methyl methacrylate and acrylonitrile can in principle be varied over a wide range. It has proven advantageous, however, if this physical modifier has a molecular weight (determined using the GPC method described in the following) of 100000 to 500000, preferably 180000 to 350000, and more preferably about 250000 to 280000, such as 263000. Especially preferred as a physical modifier is a copolymer composed of 91% by weight methyl methacrylate and 9% by weight acrylonitrile. The production of such copolymers is known. For example, reference is made to DE 197 33 799 A1 -and the literature cited therein. The addition of the physical modifiers to the filament-forming polyesters and copolyesters is advantageously performed ahead of the extruder, whereby the fiber polymer and additives should be in granular form. In melting the granules, the extruder in this case ensures a uniform distribution of the additives in the fiber polymer. Other static and/or dynamic mixers can be provided in the melt line and/or directly ahead of the spinning pack. The addition can also take place, however, by mixing the melt of fiber polymer with the melt of additives using static and/or dynamic mixers. Practically all known spinning methods are suitable for producing fibers from the polyesters and copolyesters of the invention. The fibers according to the invention can be readily produced using practically all winding speeds that are technically possible, in particular those from 500 to 10000 m/min. It is a service of the present invention that, even at winding speeds of up to 8000 m/min, partially oriented yarns, i.e., yarns that have not yet been drawn to the elongation at break required by the respective application, can be produced without slips. These yarns are optimally suited for further processing. Textile yarns can be further processed in a particularly advantageous manner into texturized yarns, for example, using conventional processes therefor. Industrial yarns are optimally suited for making tire cords. Melt-spinning processes as described in DE-PS 29 25 006, for example, are especially suitable. In consequence, the present invention also relates to a process for producing filament-forming polyesters and copolyesters by initially adding, to the polyester-forming starting components during polymer production, chemical modifiers in the form of chain- branching agents to be condensed-in and then adding physical modifiers to the resulting chain-branched polyester or copolyester in the form of polymer additives that do not substantially form chemical bonds with this polyester or copolyester, the process characterized in that the addition of physical and chemical modifiers is selected such that the ratio of the weight percentages, referred to the filament-forming.polyesters and co-polyesters, of chemical to physical modifiers is between 0.001 and 0.5. In the process of the invention, it is preferred for the ratio of the weight percentages, referred to the filament-forming polyesters and copolyesters, of chemical to physical modifiers to be between 0.005 and 0.25, and more preferably between 0.015 and 0.05. For the process of the invention, it is advantageous for the chemical modifiers to be present in a weight percentage between 0.005 and 0.05, referred to the filament-forming polyesters and copolyesters. In the process of the invention, it is preferred for the physical modifiers to have a weight percentage between 0.1 and 5, referred to the filament-forming polyesters and copolyesters. For the process of the invention, it is advantageous for the chemical modifiers to have at least three ester-forming hydroxyl or carboxyl groups, which are especially preferred to be selected from the group comprising trimellitic acid, pyromellitic acid, trimethylol propane, pentaerythritol, glycerin, or corresponding hydroxy acids. It is even more preferred in the process of the invention for the chemical modifiers used to contain at least six ester-forming hydroxyl groups, whereby the especially advantageous chemical modifiers have proven to be those selected from the group comprising dipentaerythritol, tripentaerythritol, and tetrapentaerythritol. For the process of the invention, it is furthermore advantageous if the ratio of the zero shear-rate viscosity of the physical modifiers to the zero shear-rate viscosity of the polyester or copolyester forming the matrix polymer is between 0.01 and 5 at the spinning temperature. In the process of the invention, it is preferred for the interface thickness a( between the physical modifiers and the polyester or copolyester forming the matrix polymer to be in the range from 6 to 50 nm at the spinning temperature. For the process of the invention, it is advantageous for the interfacial tension between the physical modifiers and the polyester or copolyester forming the matrix polymer to be in the range from 0.8 mN/m to 0.008 mN/m at the spinning temperature. In the process of the invention, it is preferred for the physical modifier to consist of substantially imidized polymethacrylic acid alkyl esters that are 50 to 90% imidized by converting polymethacrylic acid esters whose ester group contains an alcohol with 1 to 6 C atoms with a primary amine with 1 to 3 C atoms. It is furthermore advantageous for the process of the invention if the physical modifier is a copolymer made from methyl methacrylate, styrene, and acrylonitrile, whereby this copolymer is composed of 50 to 98% by weight methyl methacrylate, 1 to 50% by weight styrene, and 2 to 30% by weight acrylonitrile. It is furthermore preferred for the process of the invention if the physical modifier is a copolymer made from methyl methacrylate and acrylonitrile, whereby this copolymer is composed of 80 to 98% by weight methyl methacrylate and 2 to 20% by weight acrylonitrile. This copolymer advantageously also has a molecular weight of 100000 to 500000 and more preferably 180000 to 350000. The present invention is also directed toward the use of the chemically and physically modified filament-forming polyesters and copolyesters for high-speed spinning of textile and industrial yarns with winding speeds of 2500 to 10000 m/min, preferably 3000 to 6000 m/min, followed by conventional drawing or texturizing processes, as well as to- ward the use of the polyesters and copolyesters modified according to the invention to increase the spinning speed and thereby the throughput during melt spinning. Furthermore, the invention relates to the use of polyesters and copolyesters for highspeed spinning of textile and industrial yarns with winding speeds of 2500 to 10000 m/min, preferably 3000 to 6000 m/min, followed by conventional drawing or texturizing processes, whereby these polyesters and copolyesters contain as a physical modifier a copolymer made from methyl methacrylate, styrene, and acrylonitrile, whereby this copolymer is composed of 50 to 98%, preferably 80%, by weight methyl methacrylate, 1 to 50%, preferably 15%, by weight styrene, and 2 to 30%, preferably 5%, by weight acrylonitrile (totaling 100% by weight). The present invention is also directed toward the use of polyesters and copolyesters for high-speed spinning of textile and industrial yarns with winding speeds of 2500 to 10000 m/min, preferably 3000 to 6000 m/min, followed by conventional drawing or texturizing processes, whereby these polyesters and copolyesters contain as a physical modifier a copolymer made from methyl methacrylate and acrylonitrile, whereby this copolymer is composed of 80 to 98%, preferably 91%, by weight methyl methacrylate and 2 to 20%, preferably 9%, by weight acrylonitrile (totaling 100% by weight). In this latter use of the polyesters and copolyesters, it is preferred for the physical modifier to have a molecular weight of 100000 to 500000, advantageously 180000 to 350000, and more advantageously about 250000 to 280000, such as 263000. The invention will be explained in more detail using the following examples. The examples are intended merely as explanation and are in no way to be interpreted as restrictive. Gel permeation chromatography (GPC): (Eluent: tetrahydrofuran; pump: Kontron 420; flow: 1.0 ml/min; injection valve: Rheodyne with 20 pi injection volume) Column combination Detector: (obtained from Polymer Standards Service, Mainz , DE): Column temperature 25°C PSS-SDV (8.0 mm x 50 mm) 500 A, 5 pm (guard column) PSS-SDV (8.0 mm x 300 mm) 500 A, 5 ^m PSS-SDV (8.0 mm x 300 mm) linear, 5 pm PSS-SDV (8.0 mm x 300 mm) linear, 5 pm Waters 410 differential refractometer; software: PSS- WinGPC, version 4.02 Sample preparation: The samples are weighed-in with tetrahydrofuran at a concentration of about 10.0 g/l and dissolved overnight. Toluene serves as the internal standard. After filtration (0.45 pm), the solution is injected. Calibration and evaluation: A calibration curve is generated using PMMA standards over the separation range of the columns (for example, between 500 D and 2000000 D). The quantification of the sample can then be obtained using the software on the basis of the PMMA-standard calibration curve. Production of a copolymer from methyl methacrylate and acrylonitrile Method 1 750 g distilled water, 1.5 g (0.2% referred to water) polyethylene oxide (Aldrich PEO 200 000, Mv ~ 200000), and 3.8 g (0.5% referred to water) sodium sulfate (Merck) are weighed into a 1 I plane-ground-joint flask provided with a nitrogen inlet, anchor agitator, and dropping funnel. This pre-mixture is heated in a water bath to 75°C while stirring at about 250 rpm and subjecting to nitrogen flushing. A mixture consisting of 228.4 g methyl methacrylate, 21.6 g acrylonitrile, 0.50 g (0.2% referred to the monomers) t-dodecylmercaptan (Aldrich), and 2.5 g (1% referred to the monomers) dilauryl peroxide (Laurox, Akzo Nobel) is then added within about 30 seconds via the dropping funnel. The batch is maintained for 1.5 hours at 75°C and then heated within 15 minutes to 90°C. This temperature is maintained for an additional 30 minutes: The batch is then filtered using a G2 frit, after first cooling somewhat if required, and washed out with about 2 I water. Drying takes place in a vacuum at 60 to 70°C. The copolymer is produced in the form of white pellets between 0.1 and 2 mm in size. The molecular weight was determined as 263000 using the previously described gel permeation chromatography. The copolymer consists of 91.4% by weight methyl meth-acryiate and 8.6 percent by weight acrylonitrile. Method 2 Method 1 was repeated, except that 1.0 g (0.4% referred to the monomers) t-dodecylmercaptan was added. The molecular weight was determined as 187000 using the previously described gel permeation chromatography. The copolymer consists of 91.4% by weight methyl meth-acrylate and 8.6% by weight acrylonitrile. Production and spinning of modified polyesters and copoiyesters Initially, polyethylene terephthalate is produced in a two-stage process. In the first stage, the transesterification, the conversion of ethylene glycol and 0.015% by weight (referred to polyethylene terephthalate) pentaerythritol as a chemical branching agent is conducted with dimethyl terephthalate (= DMT), whereby the molar ratio of ethylene glycol to DMT is 2.15:1 and the transesterification is conducted in the presence of 100 ppm zinc acetate (ZnAc2 • 2H20) and 150 ppm MnAc2 ■ 4H20 (Ac = acetate) as trans- esterification catalysts, with respect to DMT, at temperatures in the range of 175 to 250°C. To avoid a sublimation of the DMT, the continuous temperature increase from 175 to 250°C is not performed too rapidly. In addition to the cited transesterification catalysts, 10 ppm M 10 defoaming agent is added. The methanol released during transesterification is distilled off via a column. When the reaction temperature of 240°C is reached, 50 ppm phosphorus, referred to DMT, is added in the form of phosphonoacetic acid ethyl ester to block the transesterification catalysts. When a temperature of 245°C is reached, 3500 ppm Ti02 suspension in ethylene glycol is added as a delustering agent. When the reaction temperature has reached 250°C, 400 ppm Sb203, as an approx. 1% solution in ethylene glycol, is added to the reaction mixture. The polycondensation reaction takes place at 290°C in a vacuum of 2.4 torr. When the melt has reached a relative solution viscosity of about 1.63, measured in 1% meta-cresol solution at 20°C, the polycondensation is terminated. The polyester so produced and chemically modified is initially dried in a conventional manner to a residual moisture of The physical modifiers used in these examples are the previously described copolymers (consisting of 91.4% by weight methyl methacrylate and 8.6% by weight acrylonitrile) in two different molecular weights. For comparison, the results of spinning PET without adding modifiers (Comp. 1) are also given. Table The table indicates that the yarns of the invention, which contain the physical and chemical modifiers in the ratio specified by the invention, have a higher elongation than the yarns modified only chemically or not at all. Filament-forming polyesters and copolyesters and process for their production - Claims: 1. Filament-forming polyesters and copolyesters containing chemical modifiers in the form of condensed-in chain-branching agents and physical modifiers in the form of polymer additives that do not substantially form chemical bonds with the filament-forming polyesters and copolyesters, characterized in that the ratio of the weight percentages, referred to the filament-forming polyesters and copolyesters, of chemical to physical modifiers is between 0.001 and 0.5. 2. Polyesters and copolyesters according to Claim 1, characterized in that the ratio of the weight percentages, referred to the filament-forming polyesters and copolyesters, of chemical to physical modifiers is between 0.005 and 0.25. 3. Polyesters and copolyesters according to Claim 1, characterized in that the ratio of the weight percentages, referred to the filament-forming polyesters and copolyesters, of chemical to physical modifiers is between 0.015 and 0.05. 4. Polyesters and copolyesters according to one or more of Claims 1 to 3, characterized in that the weight percentage, referred to the filament-forming polyesters and copolyesters, of the chemical modifiers is between 0.005 and 0.05. 5. Polyesters and copolyesters according to one or more of Claims 1 to 4, characterized in that the weight percentage, referred to the filament-forming polyesters and copolyesters, of the physical modifiers is between 0.1 and 5. 6. Polyesters and copolyesters according to one or more of Claims 1 to 5, characterized in that the chemical modifiers contain at least three ester-forming hydroxyl or carboxyl groups. 7. Polyesters and copolyesters according to one or more of Claims 1 to 6, characterized in that the chemical modifiers are selected from the group comprising trimellitic acid, pyromeilitic acid, trimethylol propane, pentaerythritol, glycerin, or corresponding hydroxy acids. 8. Polyesters and copolyesters according to one or more of Claims 1 to 5, characterized in that the chemical modifiers contain at least six ester-forming hydroxyl groups. 9. Polyesters and copolyesters according to Claim 8, characterized in that the chemical modifiers are selected from the group comprising dipentaerythritol, tripentaerythritol, and tetrapentaerythritol. 10. Polyesters and copolyesters according to one or more of Claims 1 to 9, characterized in that the ratio of the zero shear-rate viscosity of the physical modifiers to the zero shear-rate viscosity of the polyester or copolyester forming the matrix polymer is between 0.01 and 5 at the spinning temperature. 11. Polyesters and copolyesters according to one or more of Claims 1 to 10, characterized in that the interface thickness a\ between the physical modifiers and the polyester or copolyester forming the matrix polymer is in the range from 6 to 50 nm at the spinning temperature. 12. Polyesters and copolyesters according to one or more of Claims 1 to 11, char acterized in that the interfacial tension between the physical modifiers and the polyester or copolyester forming the matrix polymer is in the range from 0.8 mN/m to 0.008 mN/m at the spinning temperature. 13. Polyesters and copolyesters according to one or more of Claims 1 to 12, characterized in that the physical modifier consists of substantially imidized polymethacrylic acid alkyl esters that are 50 to 90% imidized by converting polymethacrylic acid esters whose ester group contains an alcohol with 1 to 6 C atoms with a primary amine with 1 to 3 C atoms. 14. Polyesters and copolyesters according to one or more of Claims 1 to 12, characterized in that the physical modifier is a copolymer made from methyl methacrylate, styrene, and acrylonitrile, whereby this copolymer is composed of 50 to 98% by weight methyl methacrylate, 1 to 50% by weight styrene, and 2 to 30% by weight acrylonitrile. 15. Polyesters and copolyesters according to one or more of Claims 1 to 12, characterized in that the physical modifier is a copolymer made from methyl methacrylate and acrylonitrile, whereby this copolymer is composed of 80 to 98% by weight methyl methacrylate and 2 to 20% by weight acrylonitrile. 16. Polyesters and copolyesters according to Claim 15, characterized in that the physical modifier has a molecular weight of 100000 to 500000, preferably 180000 to 350000. 17. Process for producing filament-forming polyesters and copolyesters by initially adding, to the polyester-forming starting components during polyester production, chemical modifiers in the form of chain-branching agents to be condensed-in and then adding, to the resulting chain-branched polyester or copolyester, physical modifiers in the form of polymer additives that do not substantially form chemical bonds with this polyester or copolyester, characterized in that the ratio of the weight percentages, referred to the filament-forming polyesters and copolyesters, of chemical to physical modifiers is between 0.001 and 0.5. 18. Process according to Claim 17, characterized in that the ratio of the weight percentages, referred to the filament-forming polyesters and copolyesters, of chemical to physical modifiers is between 0.005 and 0.25. 19. Process according to Claim 17, characterized in that the ratio of the weight percentages, referred to the filament-forming polyesters and copolyesters, of chemical to physical modifiers is between 0.015 and 0.05. 20. Process according to one or more of Claims 17 to 19, characterized in that the weight percentage, referred to the filament-forming polyesters and copolyesters, of the chemical modifiers is between 0.005 and 0.05. 21. Process according to one or more of Claims 17 to 19, characterized in that the weight percentage, referred to the filament-forming polyesters and copolyesters, of the physical modifiers is between 0.1 and 5. 22. Process according to one or more of Claims 17 to 21, characterized in that the chemical modifiers contain at least three ester-forming hydroxy! or carboxyl groups. 23. Process according to Claim 22, characterized in that the chemical modifiers are selected from the group comprising trimellitic acid, pyromellitic acid, trimethylol propane, pentaerythritol, glycerin, or corresponding hydroxy acids. 24. Process according to one or more of Claims 17 to 21, characterized in that the chemical modifiers contain at least six ester-forming hydroxyl groups. 25. Process according to Claim 24, characterized in that the chemical modifiers are selected from the group comprising dipentaerythritol, trip6ntaerythritol, and tet-rapentaerythritol. 26. Process according to one or more of Claims 17 to 25, characterized in that the ratio of the zero shear-rate viscosity of the physical modifiers to the zero shear-rate viscosity of the polyester or copolyester forming the matrix polymer is between 0.01 and 5 at the spinning temperature. 27. Process according to one or more of Claims 17 to 25, characterized in that the interface thickness a; between the physical modifiers and the polyester or co-polyester forming the matrix polymer is in the range from 6 and 50 nm at the spinning temperature. 28. Process according to one or more of Claims 17 to 25, characterized in that the interfacial tension between the physical modifiers and the polyester or copolyester forming the matrix polymer is in the range from 0.8 mN/m and 0.008 mN/m at the spinning temperature. 29. Process according to one or more of Claims 17 to 28, characterized in that the physical modifier consists of substantially imidized polymethacrylic acid alkyl esters that are 50 to 90% imidized by converting polymethacrylic acid esters whose ester group contains an alcohol with 1 to 6 C atoms with a primary amine with 1 to 3 C atoms. 30. Process according to one or more of Claims 17 to 28, characterized in that the physical modifier is a copolymer made from methyl methacrylate, styrene, and acrylonitrile, whereby this copolymer is composed of 50 to 98% by weight methyl methacrylate, 1 to 50% by weight styrene, and 2 to 30% by weight acrylonitrile. 31. Process according to one or more of Claims 17 to 28, characterized in that the physical modifier is a copolymer made from methyl methacrylate and acrylonitrile, whereby this copolymer is composed of 80 to 98% by weight methyl methacrylate and 2 to 20% by weight acrylonitrile. 32. Process according to Claim 31, characterized in that the physical modifier has a molecular weight of 100000 to 500000, preferably 180000 to 350000. 33. Use of the polyesters and copolyesters according to Claims 1 to 16 for highspeed spinning of textile and industrial yarns with winding speeds of 2500 to 10000 m/min, preferably 3000 to 6000 m/min, followed by conventional drawing ortexturizing processes. 34. Use of polyesters and copolyesters according to Claims 1 to 16 to increase the spinning speed and thus the throughput during melt spinning. 35. Use of polyesters and copolyesters according to one or more of Claims 1 to 16 for high-speed spinning of textile and industrial yams with winding speeds of 2500 to 10000 m/min, preferably 3000 to 6000 m/min, followed by conventional drawing or texturizing processes, characterized in that these polyesters and co-polyesters contain as a physical modifier a copolymer made from methyl methacrylate, styrene, and acrylonitrile, whereby this copolymer is composed of 50 to 98% by weight methyl methacrylate, 1 to 50% by weight styrene, and 2 to 30% by weight acrylonitrile. 36. Use of polyesters and copolyesters according to one or more of Claims 1 to 16 for high-speed spinning of textile and industrial yarns with winding speeds of 2500 to 10000 m/min, preferably 3000 to 6000 m/min, followed by conventional drawing or texturizing processes, characterized in that these polyesters and copolyesters contain as a physical modifier a copolymer made from methyl methacrylate and acrylonitrile, whereby this copolymer is composed of 80 to 98% by weight methyl methacrylate and 2 to 20% by weight acrylonitrile. 37. Use of the polyesters and copolyesters according to Claim 36, characterized in that the physical modifier has a molecular weight of 100000 to 500000, preferably 180000 to 350000. 38. Filament-forming polyesters and copolyesters substantially as herein described and exemplified. 39. Process for producing filament-forming polyesters substantially as herein described and exemplified.

Full Text

Description:
The invention relates to filament-forming polyesters and copolyesters containing chemical modifiers in the form of condensed-in chain-branching agents and physical modifiers in the form of polymer additives that do not substantially form chemical bonds with the filament-forming polyesters and copolyesters, and a process for their production. The invention further relates to the use of these polyesters and copolyesters for high-speed spinning of textile and industrial yarns.
Filament-forming chain-branched polyesters and copolyesters having very slight amounts of chain-branching agents are known. DE 27 28 095 A1 describes filament-forming chain-branched polyesters and copolyesters having very slight amounts of pentaerythritol or other polyfunctional compounds such as glycerin, trimethylol propane, or mellitic acid. Using the tetrafunctional branching agent pentaerythritol as a chain-branching agent, high residual elongations and resulting productivity gains are obtained from added amounts ranging from 500 to 625 ppm, whereas with lower added amounts ranging from about 100 to 200 ppm the residual elongations and resulting productivity gains are reduced considerably (see Table I of DE 27 28 095 A1). In the case of high added amounts of pentaerythritol, the high degree of branching of the corresponding polyesters results in properties for the POY yarns used in further processing that differ considerably from the conventional polyester yarns, whose valued and proven proper-

ties it is naturally desirable to maintain, and unacceptable interactions of the yarn properties develop at spinning speeds of 4023 m/min or higher (see Table II of DE-OS 27 28
095).
Progress in this direction is shown by WO 98/47936, which discloses filament-forming chain-branched polyesters and copolyesters with a molecular weight of > 10000 and which are obtained by condensing into the polyester-forming starting components 50 to 500 ppm of one or more of the chain-branching agents di-, tri- or tetrapentaerythritol added during polymer production. According to WO 98/47936, these polyesters and copolyesters are excellently suited for high-speed spinning of textile and industrial yarns with winding speeds of 2500 to 10000 m/min.
However, the increased crystallinity of such modified polyesters and copolyesters in processes downstream from the spinning process, in particular in texturizing, can result in processing problems, which in adverse situations can lead to partial or total loss of the productivity gains realized during spinning.
There are also a number of publications known in the art in which the filament-forming polyesters and copolyesters contain physical modifiers in the form of polymer additives, which do not substantially form chemical bonds with the filament-forming polyesters and copolyesters.
WO 93/19231 describes fibers made primarily from polyethylene terephthalate as a fiber polymer, the fibers characterized in that they contain 0.1 to 5% by weight, referred to the fiber polymer, of a 50 to 90% imidized polymethacrylic acid alkyl ester mainly in interstitial form. According to this document, spinning at very high rates (such as 8000 m/min) is possible while maintaining conventional thread-breakage counts.
DE 197 33 799 A1 makes known the use of copolymers of methyl methacrylate, maleic acid anhydride, and/or maleic imides and possibly other ethylenic unsaturated and therefore copolymerizable monomers as additives to fiber polymers based on polyal-

kylene terephthalates in amounts of 0.1 to 5% by weight. The addition of these copolymers is intended to improve the melt-spinning properties of polyester filament yarns after high-speed and super-high-speed spinning with drawing-off speeds of 500 to 10000 m/min.
Finally, DE 197 07 447 A1 discloses copolymers added to the polyester or polyamide in amounts of 0.05 to 5 percent by weight, and constructed from at least two of the following monomer units:
A = monomer of acrylic acid or methacrylic acid alkyl ester type B = monomer of maleic acid or maleic acid anhydride type C = monomer of styrene type
with = to 90% by weight A, 0 to 40% by weight B, and 5 to 85% by weight C (totaling 100%).
According to the latter document, these physical modifiers do not restrict in particular the behavior in further-processing steps, and this despite increased spinning speed. According to DE 197 07 447 A1, in the case of polyethylene terephthalate (PET) as a matrix polymer, a slight fraction of branching components can be included, such as polyfunctional acids like trimellitic or pyromellitic acid, ortri- ortetravalent alcohols such as trimethylol propane, pentaerythritol, or corresponding hydroxy acids.
In the spinning of polyesters and copolyesters, in particular polyethylene terephthalate, modified with physical modifiers, as disclosed in WO 93/19231, DE 19733 799 A1, and DE 197 07 447 A1, however, problems can arise during winding , which manifest themselves especially at higher speeds, i.e., above 3000 m/min, particularly above 5000 m/min. On the one hand, there is an increase of so-called slips. Slips are known to those skilled in the art as flaws that arise during winding when a filament section slips laterally. This places problem-free pull-off of the material in further processing in question.

On the other hand, a further disadvantage in spinning, particularly in high-speed spinning, is the tendency of the physically modified polyesters and copolyesters to form swells during winding onto the spool. Swells are likewise known to those skilled in the art as spooling flaws and lead for example to problems in packaging and shipment of the finished spools.
The object of the present invention is to provide new filament-forming polyesters and copolyesters which at least reduce the previously described disadvantages in the prior art.
Surprisingly, it was found that the object of the invention can be satisfied by filament-forming polyesters and copolyesters containing chemical modifiers in the form of con-densed-in chain-branching agents and physical modifiers in the form of polymer additives that do not substantially form chemical bonds with the filament-forming polyesters and copolyesters, these polyesters and copolyesters being characterized in that the ratio of the weight percentages, referred to the filament-forming polyesters and copolyesters, of chemical to physical modifiers is between 0.001 and 0.5.
Preferred polyesters and copolyesters are obtained by setting the ratio of the weight percentages of chemical to physical modifiers, each referred to the filament-forming polyesters and copolyesters, between 0.005 and 0.25, and a ratio between 0.015 and 0.05 is especially preferred.
Even at high winding speeds of 2500 to 10000 m/min, the polyesters and copolyesters of the invention surprisingly do not exhibit the problems known in the prior art that result when using only one of the two modifiers or a combination of chemical and physical modifiers outside the claimed range. The advantageous behavior of the polyesters and copolyesters in accordance with the present invention manifests itself in particular in practically slip-free winding at spinning speeds between 2500 and 10000 m/min, in particular between 3000 and 6000 m/min. The crystallinity of these polyesters and copolyesters is such that, even in steps downstream from the spinning process such as tex-

turizing, a processing speed can be attained that is at least at the level of unmodified polyesters and copolyesters.
The present invention therefore makes it possible to maintain the increase in spinning speed known in the prior art by adding chemical or physical modifiers and at the same time, by setting a specific quantity ratio between physical and chemical modifiers, to provide polyesters and copolyesters that are capable of solving the previously described problems in the prior art.
Polyesters and copolyesters with a weight ratio according to the invention are not disclosed by DE 197 07 447 A1 and are also not suggested by this specification.
The assumed cause for the speed-increasing action of certain physical and chemical modifiers is known to those skilled in the art from WO 93/19231 and WO 98/47936, for example. In both cases, the residual elongation of polyesters and copolyesters modified in this manner is higher compared to the unmodified compounds. To attain the same residual elongation as with unmodified polyesters and copolyesters, the modified polyesters and copolyesters can therefore be wound up at correspondingly higher speed, thereby increasing the throughput in melt spinning.
One service provided by the polyesters and copolyesters according to the invention is that the effects of both modifiers in increasing spinning speed are also maintained in the ratio according to the invention. This means that the overall increase in melt-spinning throughput can indeed be the sum of the contributions of both modification types. A synergistic effect with respect to spinning speed, i.e., an increase over and above the mere additive effect of both modifiers, is conceivable using the polyesters and copolyesters of the invention, but it could not be experimentally verified up to now. However, it has been noted that the polyesters and copolyesters according to the present invention exhibit the aforementioned advantages over and above the mere addition of the effects increasing spinning speed

One skilled in the art can determine the concentrations of chemical and physical modifiers by simple trials. The polyesters and copolyesters of the invention generally contain the chemical modifiers in weight percentages between 0.005 and 0.05. An amount of 0.005 to 0.025 is preferred, and 0.005 to 0.015, for example 0.011% by weight (110 ppm), is even more preferred. The weight percentages are referred in each case to the filament-forming polyesters and copolyesters.
The physical modifiers are used in amounts between 0.1 and 5% by weight, referred to the filament-forming polyesters and copolyesters. A range of 0.1 to 1% by weight is preferred, and 0.3 to 1% by weight, for example 0.7% by weight (7000 ppm) is even more preferred.
Of course, several different chemical and/or physical modifiers can be present simultaneously in the polyesters and copolyesters of the invention, as long as the weight ratios remain in the claimed ranges. It is preferable, however, to use only one type of chemical and physical modifier, respectively.
The chemical modifiers are chain-branching agents, preferably low-molecular, and therefore contain at least three functional groups that are suitable for reacting with the polyester-forming starting components. In this case, and for the subsequently cited chemical modifiers, the number of functionalities or functional groups in each case refers of course to the number before the reaction with the polyester- or copolyester-forming starting components.
Preferred polyester-forming starting components are those diols and dicarboxylic acids, or derivatives thereof such as dicarboxylic acid diesters, that lead to the formation of polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, poly(ethylene-2,6-naphthalene dicarboxylate), poly(butylene-2,6-naphthalene dicar-boxylate), poly(1,4-dimethylenecyclohexane terephthalate), or polyester blends thereof on the basis of high homopolyester fractions of at least 90 mole percent. The remaining dicarboxylic-acid and diol components of these polyester blends can, in amounts up to

10 mole percent, be the conventional co-components in producing drawn polyester structures, such as isophthalic acid, p,p'-diphenyl dicarboxylic acid, all possible naphthalene dicarboxyiic acids, hexahydroterephthalic acid, adipic acid, sebacic acid, and glycols such as trimethylene, tetramethylene, hexamethylene, and decamethylene glycol.
Suitable chain-branching agents that can react with the polyester-forming starting components include chemical modifiers that have at least three ester-forming hydroxyl or carboxyl groups. Preferred modifiers are trimellitic acid, pyromellitic acid, trimethylol propane, pentaerythritol, glycerin, or the corresponding hydroxy acids. Of course, the group of chain-branching agents need not be limited to compounds having ester-forming hydroxyl and carboxyl groups. Also possible, of course, are other functional groups such as amino or isocyanate groups. The selection of the chemical modifiers is limited only by the requirement that the stability of the compounds used be sufficient to withstand the reaction conditions prevailing in polyester synthesis, such that a branching reaction is substantially possible.
Preferred for the present invention, however, are polyesters and copolyesters modified with chemical modifiers having at least six ester-forming hydroxyl groups.
Of these latter chemical modifiers, those selected from the group comprising dipentae-rythritol, tripentaerythritol, and tetrapentaerythritol are especially preferred. Such modifiers are known from WO 98/47936, for example.
The production of chain-branched polyesters and copolyesters is known per se. Since the chain-branched polyesters and copolyesters can also be categorized in particular as chemically modified homopolyesters and copolyesters, it is not even necessary when producing them to modify the production method for the homopolyesters and copolyesters concerned, such as the transesterification and polycondensation conditions. The only difference is that the chain-branching agents be added in the required weight percentages to the corresponding polyester-forming starting components during polyester

production, which is otherwise conventional. This is illustrated using the especially preferred chain-branched polyester in the scope of the present invention, which is obtained by adding chain-branching agent(s) leading to formation of polyethylene tereph-thalate to the polyester-forming starting components.
The production of polyethylene terephthalate can proceed in a known manner in two reaction stages. The first reaction stage, which can be conducted continuously or discontinuous^, consists in the transesterification of dimethyl terephthalate with ethylene glycol to form bis(2-hydroxyethyl) terephthalate using transesterification catalysts at 150-200°C, for example, or in the direct esterification of terephthalic acid with ethylene glycol at about 260°C under pressure, which generally requires no catalyst and which also forms bis(2-hydroxyethyl) terephthalate. Through oligocondensation reactions, which take place under the transesterification and direct esterification conditions themselves, lesser or greater amounts of linear oligomers of bis(2-hydroxyethyl) terephthalate are formed in addition. A preferred embodiment according to the invention consists in adding the chain-branching agent(s), before or during the transesterification reaction or the direct esterification, to the polyester-forming starting components, in the present case to dimethyl terephthalate and ethylene glycol or to terephthalic acid and ethylene glycol, such that a uniformly reacting mixture can develop. After transesterification has ended, it is advantageous to block, in a manner known per se, any transesterification catalysts present by adding one or more phosphorus compounds. Blocking agents include in particular carbethoxymethyl diethyl phosphonate,
di(polyoxyethylene)hydroxymethyl phosphonate, tetraisopropyl methylene diphospho-nate, phosphonoacetic acid ethyl ester and/or H3P04, whereby a concentration of added P of 30-50 ppm is generally sufficient.
If the production of bis(2-hydroxyethyl) terephthalate and its. oligomers is conducted by adding ethylene oxide to terephthalic acid, terephthalic acid and ethylene oxide by nature represent the polyester-forming starting components. The term polyester-forming starting components fundamentally includes all dicarboxylic-acid and diol derivatives, for example also dicarboxylic acid chlorides or diol diacetates, that are suited to forming

the polyesters and copolyesters known per se, which in turn are subjected during the polyester and copolyester synthesis to a modification by the chain-branching agents.
The second reaction stage, which can be conducted continuously or discontinuously, consists in the polycondensation of bis(2-hydroxyethyl) terephthalate and its oligomers to form polyethylene terephthalate at 280~290°C, for example, in a vacuum using known polycondensation catalysts. A further preferred embodiment of the invention consists in the possibility of adding the chain-branching agent(s) to the polyester-forming starting components, in the present case to bis(2-hydroxyethyl) terephthalate and its oligomers, even before this melt polycondensation. While addition of the chain-branching agents in the initial part of the polycondensation stage is also possible in principle, it is not as preferred.
The chain-branched polyethylene terephthalate produced in this manner has an intrinsic viscosity of 0.70 to 0.75, corresponding to a relative solution viscosity of 1.63 to 1.70, measured in 1% meta-cresol solution at 20°C.
If the chain-branched polyethylene terephthalate is to be used to manufacture industrial yarns, such as for use in tire cords, its molecular weight must be increased in a manner analogous to the case of polyethylene terephthalate. This can be achieved using processes known per se developed for polyethylene terephthalate, including its conversion with agents that increase the degree of polymerization, such as 2,2'-bis(2-oxazoline), in accordance with EP-A-0 169 415. The required increase in intrinsic viscosity to 0.95-1.05, for example, corresponding to a relative solution viscosity of 1.86 to 2.05, measured in 1% meta-cresol solution at 20°C, is preferably achieved using a final polycondensation in the solid phase, as is also the practice for polyethylene terephthalate. In this case, the granular chain-branched polyethylene terephthalate is heated in a vacuum or an inert gas stream to temperatures below the melting point, such as to 230°C.
The second component in the filament-forming polyesters and copolyesters of the invention is represented by the physical modifier. The physical modifiers are compounds,

preferably polymeric, that do not substantially form chemical bonds with the filament-forming polyesters and copolyesters. They are generally only partially soluble in the matrix polymer formed from the filament-forming polyesters and copolyesters. In order for these physical modifiers or additives to be effective in such a way that leads to an increase in spinning speed and'throughput during melt spinning, the interface between the polymer matrix and physical modifiers should be as large as possible. In the case of polymer additives, a large interface is typically attained if these additives form fibrils during the spinning process in which the ratio of surface area to volume is large. Suitable additives must therefore, of course, be plastic at the melt-spinning temperature.
It has proven advantageous for the ratio of the zero shear-rate viscosity of the additive to the zero shear-rate viscosity of the matrix polymer (e.g., the chemically modified or unmodified polyethylene terephthalate) to be between 0.01 and 5, preferably between 0.5 and 2, at the spinning temperature. The zero shear-rate viscosity of the polymers is determined in this case using the method described in G. Bohme, Stromunqsmechanik nicht-newtonscher Fluide [Flow Mechanics of Non-Newtonian Fluids], Verlag Teubner Studienbucher (1981).
Another important criterion in selecting the physical modifier is that the additive solidifies significantly before the surrounding polymer matrix during the spinning process. For one skilled in the art, this means that the solidification temperature (i.e., the increase in zero shear-rate viscosity towards infinity) of the additive takes place at higher temperatures than the corresponding zero shear-rate viscosity increase of the surrounding matrix polymer. The glass transition temperature of the additive should be higher than that of the matrix polymer.
In addition to the previously cited, general parameters for selecting suitable physically effective additives, at least one of the following criteria, which can be determined by measurement and/or calculation and which describe the interactions between the physical modifier (additive) and the matrix polymer, should be fulfilled.

For one, the interface thickness a, between the additive and surrounding matrix should be in the range from 6 to 50 nm, preferably from 10 to 15 nm, in'the tanh interface profile at the spinning temperature.
Methods for experimental characterization of interface thicknesses are known to those skilled in the art. For example, X-ray or neutron reflection, nuclear reaction analysis, NMR, or electron transmission microscopy. These methods are extremely complex and expensive, however. It has proven advantageous, therefore, to estimate the interface thickness using mean-field theory.
In a 2-phase (phases 1 and 2), 2-component (components A and B) system, the following tanh interface profile applies:

where
O(z) = volume fraction at z
z = depth perpendicular to the phase interface (z = 0 at phase interface)
a{ = interface thickness
Oi* = bulk volume fraction of component (A or B) in phase i
For the interface thickness a; between two polymer components A and B (D. Broseta, G. Fredrickson, E. Helfand, L. Leibler, Macromolecules 23, 132 (1990), Ralf Schnell dissertation 1997, Johannes Gutenberg University, Mainz (Germany), the following applies:

where
a; = interface thickness
b = mean Kuhn segment length (approx. 0.7 nm)
c = correction factor (= 9 for the limiting case in which the gyration radius of
the chains is much smaller that the interface thickness) (= 6 in the case of strongly incompatible polymers, in which the interface thickness is significantly smaller that the gyration radius)
%AB = Flory-Huggins interaction parameter between the polymer components A
and B
Nj = Degree of polymerization of the polymer component i
The Flory-Huggins interaction parameter required in the calculation can be estimated as follows using the solubility parameters of the polymer components A and B:

where
^AB = Flory-Huggins interaction parameter between the polymer components A
and B
Vref = Reference volume (30 ccm/mol, for example, provides good results for the
well-characterized polystyrene/polymethyl methyacrylate system. According to Bicerano, however, 100 ccm/mol is also used.)
5j = solubility parameter of the polymer component i (according to J. Bicerano,
Prediction of Polymer Properties, Marcel Dekker Verlag, Inc., New York (1993))
R = gas constant (8.314 J*K-1*mol-1)
T = temperature in Kelvin

The polymer phases A and B are generally more compatible the smaller the difference of their solubility parameters and the higher the temperature. '
A further criterion for selecting suitable physical additives is the interfacial tension y between the additive and the surrounding polymer matrix. This interfacial tension should be in the range from 0.8 mN/m to 0.008 mN/m, preferably 0^5 to 0.3 mN/m, at the spinning temperature. The interfacial tension is measured using the pendant or spinning drop geometry method (A. Stammer, dissertation 1997, Johannes Gutenberg University, Mainz (Germany)).
In practice, however, the experimentally simpler extrapolation of temperature-dependent contact-angle studies to the spinning temperature has proven very helpful.
Furthermore, the interfacial tension yean be estimated, analogously to the interface thickness a^ using mean-field theory (D. Broseta, G. Fredrickson, E. Helfand, L. Leibler, Macromolecules 23, 132 (1990)):

where
y = interfacial tension
k = Boltzmann constant
T = temperature in Kelvin
XAB = Flory-Huggins interaction parameter between the polymer components A
and B
N, = degree of polymerization of polymer component i
The final criterion for selecting the physical modifiers is the adhesion between the phases. This phase adhesion should exceed 30 J/m2, preferably even80 J/m2. The adhesion between polymers is determined using the asymmetric double cantilever beam

(ADCB) method as described in H. R. Brown, Annual Reviews in Materials Science 21. 463 (1991). In this case, tempering to the spinning temperature-is first performed and the adhesion between the polymers is then measured at room temperature.
Suitable physical additives for producing the filament-forming polyesters and copolyesters of the invention can be found in patent specifications WO 93/19231, WO 98/27158, DE 197 33 799 A1, DE 197 07 447 A1, and EP 0 047 464 B2, for example.
Preferred polyesters and copolyesters are obtained when the physical modifier consists of substantially imidized polymethacrylic acid alkyl esters that are 50 to 90% imidized by converting polymethacrylic acid esters whose ester group contains an alcohol with 1 to 6 C atoms with a primary amine with 1 to 3 C atoms. This physical additive and its use for polyethylene terephthalate is described in detail in WO 93/19231, to which explicit reference is hereby made.
Other preferred polyesters and copolyesters are obtained in that the physical modifier is a copolymer made from methyl methacrylate, styrene, and acrylonitrile, whereby this copolymer is composed of 50 to 98% by weight methyl methacrylate, 1 to 50% by weight styrene, and 2 to 30% by weight acrylonitrile (totaling 100%). Especially preferred as a physical modifier is a copolymer composed of 80% by weight methyl methacrylate, 15% by weight styrene, and 5% by weight acrylonitrile.
Finally, filament-forming polyesters and copolyesters are preferred in which the physical modifier is a copolymer made from methyl methacrylate and acrylonitrile, whereby this copolymer is composed of 80 to 98% by weight methyl methacrylate and 2 to 20% by weight acrylonitrile (totaling 100%). The molecular weight of the copolymers made from methyl methacrylate and acrylonitrile can in principle be varied over a wide range. It has proven advantageous, however, if this physical modifier has a molecular weight (determined using the GPC method described in the following) of 100000 to 500000, preferably 180000 to 350000, and more preferably about 250000 to 280000, such as 263000. Especially preferred as a physical modifier is a copolymer composed of 91% by weight

methyl methacrylate and 9% by weight acrylonitrile. The production of such copolymers is known. For example, reference is made to DE 197 33 799 A1 -and the literature cited therein.
The addition of the physical modifiers to the filament-forming polyesters and copolyesters is advantageously performed ahead of the extruder, whereby the fiber polymer and additives should be in granular form. In melting the granules, the extruder in this case ensures a uniform distribution of the additives in the fiber polymer. Other static and/or dynamic mixers can be provided in the melt line and/or directly ahead of the spinning pack.
The addition can also take place, however, by mixing the melt of fiber polymer with the melt of additives using static and/or dynamic mixers.
Practically all known spinning methods are suitable for producing fibers from the polyesters and copolyesters of the invention. The fibers according to the invention can be readily produced using practically all winding speeds that are technically possible, in particular those from 500 to 10000 m/min.
It is a service of the present invention that, even at winding speeds of up to 8000 m/min, partially oriented yarns, i.e., yarns that have not yet been drawn to the elongation at break required by the respective application, can be produced without slips. These yarns are optimally suited for further processing. Textile yarns can be further processed in a particularly advantageous manner into texturized yarns, for example, using conventional processes therefor. Industrial yarns are optimally suited for making tire cords. Melt-spinning processes as described in DE-PS 29 25 006, for example, are especially suitable.
In consequence, the present invention also relates to a process for producing filament-forming polyesters and copolyesters by initially adding, to the polyester-forming starting components during polymer production, chemical modifiers in the form of chain-

branching agents to be condensed-in and then adding physical modifiers to the resulting chain-branched polyester or copolyester in the form of polymer additives that do not substantially form chemical bonds with this polyester or copolyester, the process characterized in that the addition of physical and chemical modifiers is selected such that the ratio of the weight percentages, referred to the filament-forming.polyesters and co-polyesters, of chemical to physical modifiers is between 0.001 and 0.5.
In the process of the invention, it is preferred for the ratio of the weight percentages, referred to the filament-forming polyesters and copolyesters, of chemical to physical modifiers to be between 0.005 and 0.25, and more preferably between 0.015 and 0.05.
For the process of the invention, it is advantageous for the chemical modifiers to be present in a weight percentage between 0.005 and 0.05, referred to the filament-forming polyesters and copolyesters.
In the process of the invention, it is preferred for the physical modifiers to have a weight percentage between 0.1 and 5, referred to the filament-forming polyesters and copolyesters.
For the process of the invention, it is advantageous for the chemical modifiers to have at least three ester-forming hydroxyl or carboxyl groups, which are especially preferred to be selected from the group comprising trimellitic acid, pyromellitic acid, trimethylol propane, pentaerythritol, glycerin, or corresponding hydroxy acids.
It is even more preferred in the process of the invention for the chemical modifiers used to contain at least six ester-forming hydroxyl groups, whereby the especially advantageous chemical modifiers have proven to be those selected from the group comprising dipentaerythritol, tripentaerythritol, and tetrapentaerythritol.
For the process of the invention, it is furthermore advantageous if the ratio of the zero shear-rate viscosity of the physical modifiers to the zero shear-rate viscosity of the

polyester or copolyester forming the matrix polymer is between 0.01 and 5 at the spinning temperature.
In the process of the invention, it is preferred for the interface thickness a( between the physical modifiers and the polyester or copolyester forming the matrix polymer to be in the range from 6 to 50 nm at the spinning temperature.
For the process of the invention, it is advantageous for the interfacial tension between the physical modifiers and the polyester or copolyester forming the matrix polymer to be in the range from 0.8 mN/m to 0.008 mN/m at the spinning temperature.
In the process of the invention, it is preferred for the physical modifier to consist of substantially imidized polymethacrylic acid alkyl esters that are 50 to 90% imidized by converting polymethacrylic acid esters whose ester group contains an alcohol with 1 to 6 C atoms with a primary amine with 1 to 3 C atoms.
It is furthermore advantageous for the process of the invention if the physical modifier is a copolymer made from methyl methacrylate, styrene, and acrylonitrile, whereby this copolymer is composed of 50 to 98% by weight methyl methacrylate, 1 to 50% by weight styrene, and 2 to 30% by weight acrylonitrile.
It is furthermore preferred for the process of the invention if the physical modifier is a copolymer made from methyl methacrylate and acrylonitrile, whereby this copolymer is composed of 80 to 98% by weight methyl methacrylate and 2 to 20% by weight acrylonitrile. This copolymer advantageously also has a molecular weight of 100000 to 500000 and more preferably 180000 to 350000.
The present invention is also directed toward the use of the chemically and physically modified filament-forming polyesters and copolyesters for high-speed spinning of textile and industrial yarns with winding speeds of 2500 to 10000 m/min, preferably 3000 to 6000 m/min, followed by conventional drawing or texturizing processes, as well as to-

ward the use of the polyesters and copolyesters modified according to the invention to increase the spinning speed and thereby the throughput during melt spinning.
Furthermore, the invention relates to the use of polyesters and copolyesters for highspeed spinning of textile and industrial yarns with winding speeds of 2500 to 10000 m/min, preferably 3000 to 6000 m/min, followed by conventional drawing or texturizing processes, whereby these polyesters and copolyesters contain as a physical modifier a copolymer made from methyl methacrylate, styrene, and acrylonitrile, whereby this copolymer is composed of 50 to 98%, preferably 80%, by weight methyl methacrylate, 1 to 50%, preferably 15%, by weight styrene, and 2 to 30%, preferably 5%, by weight acrylonitrile (totaling 100% by weight).
The present invention is also directed toward the use of polyesters and copolyesters for high-speed spinning of textile and industrial yarns with winding speeds of 2500 to 10000 m/min, preferably 3000 to 6000 m/min, followed by conventional drawing or texturizing processes, whereby these polyesters and copolyesters contain as a physical modifier a copolymer made from methyl methacrylate and acrylonitrile, whereby this copolymer is composed of 80 to 98%, preferably 91%, by weight methyl methacrylate and 2 to 20%, preferably 9%, by weight acrylonitrile (totaling 100% by weight).
In this latter use of the polyesters and copolyesters, it is preferred for the physical modifier to have a molecular weight of 100000 to 500000, advantageously 180000 to 350000, and more advantageously about 250000 to 280000, such as 263000.
The invention will be explained in more detail using the following examples. The examples are intended merely as explanation and are in no way to be interpreted as restrictive.
Gel permeation chromatography (GPC):
(Eluent: tetrahydrofuran; pump: Kontron 420; flow: 1.0 ml/min;
injection valve: Rheodyne with 20 pi injection volume)

Column combination
Detector:

(obtained from Polymer Standards Service, Mainz , DE):
Column temperature 25°C
PSS-SDV (8.0 mm x 50 mm) 500 A, 5 pm (guard column)
PSS-SDV (8.0 mm x 300 mm) 500 A, 5 ^m
PSS-SDV (8.0 mm x 300 mm) linear, 5 pm
PSS-SDV (8.0 mm x 300 mm) linear, 5 pm
Waters 410 differential refractometer; software: PSS-
WinGPC, version 4.02

Sample preparation:

The samples are weighed-in with tetrahydrofuran at a concentration of about 10.0 g/l and dissolved overnight. Toluene serves as the internal standard. After filtration (0.45 pm), the solution is injected.

Calibration and evaluation:
A calibration curve is generated using PMMA standards over the separation range of the columns (for example, between 500 D and 2000000 D). The quantification of the sample can then be obtained using the software on the basis of the PMMA-standard calibration curve.
Production of a copolymer from methyl methacrylate and acrylonitrile
Method 1
750 g distilled water, 1.5 g (0.2% referred to water) polyethylene oxide (Aldrich PEO 200 000, Mv ~ 200000), and 3.8 g (0.5% referred to water) sodium sulfate (Merck) are weighed into a 1 I plane-ground-joint flask provided with a nitrogen inlet, anchor agitator, and dropping funnel. This pre-mixture is heated in a water bath to 75°C while stirring at about 250 rpm and subjecting to nitrogen flushing. A mixture consisting of 228.4 g methyl methacrylate, 21.6 g acrylonitrile, 0.50 g (0.2% referred to the

monomers) t-dodecylmercaptan (Aldrich), and 2.5 g (1% referred to the monomers) dilauryl peroxide (Laurox, Akzo Nobel) is then added within about 30 seconds via the dropping funnel.
The batch is maintained for 1.5 hours at 75°C and then heated within 15 minutes to 90°C. This temperature is maintained for an additional 30 minutes: The batch is then filtered using a G2 frit, after first cooling somewhat if required, and washed out with about 2 I water. Drying takes place in a vacuum at 60 to 70°C.
The copolymer is produced in the form of white pellets between 0.1 and 2 mm in size. The molecular weight was determined as 263000 using the previously described gel permeation chromatography. The copolymer consists of 91.4% by weight methyl meth-acryiate and 8.6 percent by weight acrylonitrile.
Method 2
Method 1 was repeated, except that 1.0 g (0.4% referred to the monomers) t-dodecylmercaptan was added.
The molecular weight was determined as 187000 using the previously described gel permeation chromatography. The copolymer consists of 91.4% by weight methyl meth-acrylate and 8.6% by weight acrylonitrile.
Production and spinning of modified polyesters and copoiyesters
Initially, polyethylene terephthalate is produced in a two-stage process. In the first stage, the transesterification, the conversion of ethylene glycol and 0.015% by weight (referred to polyethylene terephthalate) pentaerythritol as a chemical branching agent is conducted with dimethyl terephthalate (= DMT), whereby the molar ratio of ethylene glycol to DMT is 2.15:1 and the transesterification is conducted in the presence of 100 ppm zinc acetate (ZnAc2 • 2H20) and 150 ppm MnAc2 ■ 4H20 (Ac = acetate) as trans-

esterification catalysts, with respect to DMT, at temperatures in the range of 175 to 250°C. To avoid a sublimation of the DMT, the continuous temperature increase from 175 to 250°C is not performed too rapidly. In addition to the cited transesterification catalysts, 10 ppm M 10 defoaming agent is added.
The methanol released during transesterification is distilled off via a column. When the reaction temperature of 240°C is reached, 50 ppm phosphorus, referred to DMT, is added in the form of phosphonoacetic acid ethyl ester to block the transesterification catalysts. When a temperature of 245°C is reached, 3500 ppm Ti02 suspension in ethylene glycol is added as a delustering agent.
When the reaction temperature has reached 250°C, 400 ppm Sb203, as an approx. 1% solution in ethylene glycol, is added to the reaction mixture. The polycondensation reaction takes place at 290°C in a vacuum of 2.4 torr. When the melt has reached a relative solution viscosity of about 1.63, measured in 1% meta-cresol solution at 20°C, the polycondensation is terminated.
The polyester so produced and chemically modified is initially dried in a conventional manner to a residual moisture of
The physical modifiers used in these examples are the previously described copolymers (consisting of 91.4% by weight methyl methacrylate and 8.6% by weight acrylonitrile) in two different molecular weights. For comparison, the results of spinning PET without adding modifiers (Comp. 1) are also given.
Table

The table indicates that the yarns of the invention, which contain the physical and chemical modifiers in the ratio specified by the invention, have a higher elongation than the yarns modified only chemically or not at all.

Filament-forming polyesters and copolyesters and process for their production -

Claims:
1. Filament-forming polyesters and copolyesters containing chemical modifiers in the form of condensed-in chain-branching agents and physical modifiers in the form of polymer additives that do not substantially form chemical bonds with the filament-forming polyesters and copolyesters, characterized in that the ratio of the weight percentages, referred to the filament-forming polyesters and copolyesters, of chemical to physical modifiers is between 0.001 and 0.5.
2. Polyesters and copolyesters according to Claim 1, characterized in that the ratio of the weight percentages, referred to the filament-forming polyesters and copolyesters, of chemical to physical modifiers is between 0.005 and 0.25.
3. Polyesters and copolyesters according to Claim 1, characterized in that the ratio of the weight percentages, referred to the filament-forming polyesters and copolyesters, of chemical to physical modifiers is between 0.015 and 0.05.
4. Polyesters and copolyesters according to one or more of Claims 1 to 3, characterized in that the weight percentage, referred to the filament-forming polyesters and copolyesters, of the chemical modifiers is between 0.005 and 0.05.

5. Polyesters and copolyesters according to one or more of Claims 1 to 4, characterized in that the weight percentage, referred to the filament-forming polyesters and copolyesters, of the physical modifiers is between 0.1 and 5.
6. Polyesters and copolyesters according to one or more of Claims 1 to 5, characterized in that the chemical modifiers contain at least three ester-forming hydroxyl or carboxyl groups.
7. Polyesters and copolyesters according to one or more of Claims 1 to 6, characterized in that the chemical modifiers are selected from the group comprising trimellitic acid, pyromeilitic acid, trimethylol propane, pentaerythritol, glycerin, or corresponding hydroxy acids.
8. Polyesters and copolyesters according to one or more of Claims 1 to 5, characterized in that the chemical modifiers contain at least six ester-forming hydroxyl groups.
9. Polyesters and copolyesters according to Claim 8, characterized in that the chemical modifiers are selected from the group comprising dipentaerythritol, tripentaerythritol, and tetrapentaerythritol.
10. Polyesters and copolyesters according to one or more of Claims 1 to 9, characterized in that the ratio of the zero shear-rate viscosity of the physical modifiers to the zero shear-rate viscosity of the polyester or copolyester forming the matrix polymer is between 0.01 and 5 at the spinning temperature.
11. Polyesters and copolyesters according to one or more of Claims 1 to 10, characterized in that the interface thickness a\ between the physical modifiers and the polyester or copolyester forming the matrix polymer is in the range from 6 to
50 nm at the spinning temperature.

12. Polyesters and copolyesters according to one or more of Claims 1 to 11, char
acterized in that the interfacial tension between the physical modifiers and the
polyester or copolyester forming the matrix polymer is in the range from
0.8 mN/m to 0.008 mN/m at the spinning temperature.
13. Polyesters and copolyesters according to one or more of Claims 1 to 12, characterized in that the physical modifier consists of substantially imidized polymethacrylic acid alkyl esters that are 50 to 90% imidized by converting polymethacrylic acid esters whose ester group contains an alcohol with 1 to 6 C atoms with a primary amine with 1 to 3 C atoms.
14. Polyesters and copolyesters according to one or more of Claims 1 to 12, characterized in that the physical modifier is a copolymer made from methyl methacrylate, styrene, and acrylonitrile, whereby this copolymer is composed of 50 to 98% by weight methyl methacrylate, 1 to 50% by weight styrene, and 2 to 30% by weight acrylonitrile.
15. Polyesters and copolyesters according to one or more of Claims 1 to 12, characterized in that the physical modifier is a copolymer made from methyl methacrylate and acrylonitrile, whereby this copolymer is composed of 80 to 98% by weight methyl methacrylate and 2 to 20% by weight acrylonitrile.
16. Polyesters and copolyesters according to Claim 15, characterized in that the physical modifier has a molecular weight of 100000 to 500000, preferably 180000 to 350000.
17. Process for producing filament-forming polyesters and copolyesters by initially adding, to the polyester-forming starting components during polyester production, chemical modifiers in the form of chain-branching agents to be condensed-in and then adding, to the resulting chain-branched polyester or copolyester, physical modifiers in the form of polymer additives that do not substantially form chemical

bonds with this polyester or copolyester, characterized in that the ratio of the weight percentages, referred to the filament-forming polyesters and copolyesters, of chemical to physical modifiers is between 0.001 and 0.5.
18. Process according to Claim 17, characterized in that the ratio of the weight percentages, referred to the filament-forming polyesters and copolyesters, of chemical to physical modifiers is between 0.005 and 0.25.
19. Process according to Claim 17, characterized in that the ratio of the weight percentages, referred to the filament-forming polyesters and copolyesters, of chemical to physical modifiers is between 0.015 and 0.05.
20. Process according to one or more of Claims 17 to 19, characterized in that the weight percentage, referred to the filament-forming polyesters and copolyesters, of the chemical modifiers is between 0.005 and 0.05.
21. Process according to one or more of Claims 17 to 19, characterized in that the weight percentage, referred to the filament-forming polyesters and copolyesters, of the physical modifiers is between 0.1 and 5.
22. Process according to one or more of Claims 17 to 21, characterized in that the chemical modifiers contain at least three ester-forming hydroxy! or carboxyl groups.
23. Process according to Claim 22, characterized in that the chemical modifiers are selected from the group comprising trimellitic acid, pyromellitic acid, trimethylol propane, pentaerythritol, glycerin, or corresponding hydroxy acids.
24. Process according to one or more of Claims 17 to 21, characterized in that the chemical modifiers contain at least six ester-forming hydroxyl groups.

25. Process according to Claim 24, characterized in that the chemical modifiers are selected from the group comprising dipentaerythritol, trip6ntaerythritol, and tet-rapentaerythritol.
26. Process according to one or more of Claims 17 to 25, characterized in that the ratio of the zero shear-rate viscosity of the physical modifiers to the zero shear-rate viscosity of the polyester or copolyester forming the matrix polymer is between 0.01 and 5 at the spinning temperature.
27. Process according to one or more of Claims 17 to 25, characterized in that the interface thickness a; between the physical modifiers and the polyester or co-polyester forming the matrix polymer is in the range from 6 and 50 nm at the spinning temperature.
28. Process according to one or more of Claims 17 to 25, characterized in that the interfacial tension between the physical modifiers and the polyester or copolyester forming the matrix polymer is in the range from 0.8 mN/m and 0.008 mN/m at the spinning temperature.
29. Process according to one or more of Claims 17 to 28, characterized in that the physical modifier consists of substantially imidized polymethacrylic acid alkyl esters that are 50 to 90% imidized by converting polymethacrylic acid esters whose ester group contains an alcohol with 1 to 6 C atoms with a primary amine with 1 to 3 C atoms.
30. Process according to one or more of Claims 17 to 28, characterized in that the physical modifier is a copolymer made from methyl methacrylate, styrene, and acrylonitrile, whereby this copolymer is composed of 50 to 98% by weight methyl methacrylate, 1 to 50% by weight styrene, and 2 to 30% by weight acrylonitrile.

31. Process according to one or more of Claims 17 to 28, characterized in that the physical modifier is a copolymer made from methyl methacrylate and acrylonitrile, whereby this copolymer is composed of 80 to 98% by weight methyl methacrylate and 2 to 20% by weight acrylonitrile.
32. Process according to Claim 31, characterized in that the physical modifier has a molecular weight of 100000 to 500000, preferably 180000 to 350000.
33. Use of the polyesters and copolyesters according to Claims 1 to 16 for highspeed spinning of textile and industrial yarns with winding speeds of 2500 to 10000 m/min, preferably 3000 to 6000 m/min, followed by conventional drawing ortexturizing processes.
34. Use of polyesters and copolyesters according to Claims 1 to 16 to increase the spinning speed and thus the throughput during melt spinning.

35. Use of polyesters and copolyesters according to one or more of Claims 1 to 16 for high-speed spinning of textile and industrial yams with winding speeds of 2500 to 10000 m/min, preferably 3000 to 6000 m/min, followed by conventional drawing or texturizing processes, characterized in that these polyesters and co-polyesters contain as a physical modifier a copolymer made from methyl methacrylate, styrene, and acrylonitrile, whereby this copolymer is composed of 50 to 98% by weight methyl methacrylate, 1 to 50% by weight styrene, and 2 to 30% by weight acrylonitrile.
36. Use of polyesters and copolyesters according to one or more of Claims 1 to 16 for high-speed spinning of textile and industrial yarns with winding speeds of 2500 to 10000 m/min, preferably 3000 to 6000 m/min, followed by conventional drawing or texturizing processes, characterized in that these polyesters and copolyesters contain as a physical modifier a copolymer made from methyl methacrylate and acrylonitrile, whereby this copolymer is composed of 80 to 98% by weight methyl methacrylate and 2 to 20% by weight acrylonitrile.
37. Use of the polyesters and copolyesters according to Claim 36, characterized in that the physical modifier has a molecular weight of 100000 to 500000, preferably 180000 to 350000.

38. Filament-forming polyesters and copolyesters substantially as herein
described and exemplified.
39. Process for producing filament-forming polyesters substantially as
herein described and exemplified.

Documents:

in-pct-2001-1526-che-abstract.pdf

in-pct-2001-1526-che-claims filed.pdf

in-pct-2001-1526-che-claims granted.pdf

in-pct-2001-1526-che-correspondnece-others.pdf

in-pct-2001-1526-che-correspondnece-po.pdf

in-pct-2001-1526-che-description(complete)filed.pdf

in-pct-2001-1526-che-description(complete)granted.pdf

in-pct-2001-1526-che-form 1.pdf

in-pct-2001-1526-che-form 26.pdf

in-pct-2001-1526-che-form 3.pdf

in-pct-2001-1526-che-form 5.pdf

in-pct-2001-1526-che-other documents.pdf

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Patent Number

211961

Indian Patent Application Number

IN/PCT/2001/1526/CHE

PG Journal Number

02/2008

Publication Date

11-Jan-2008

Grant Date

13-Nov-2007

Date of Filing

05-Nov-2001

Name of Patentee

M/S. DIOLEN INDUSTRIAL FIBERS GMBH

Applicant Address

KASINOSTRASSE 19-21, D-42103 WUPPERTAL,

Inventors:

#	Inventor's Name	Inventor's Address
1	VIETH, Christian	Siedlungstrasse 3d, D-63939 Worth,
2	SCHNELL, Ralf	Alfred Delp Weg 7, D-63128 Dietzenbach,
3	BATZILLA, Thomas	Konigsberger Strasse 16, D-63927 Burgstadt,

PCT International Classification Number

C08G 63/20

PCT International Application Number

PCT/EP00/04083

PCT International Filing date

2000-05-06

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	19921367.4	1999-05-10	Germany